The potassium ion is not intrinsically alkaline (nor intrinsically acidic for that matter). The pH depends what potassium is attached to; it depends on the whole molecule. For example, potassium bitartrate in a saturated solution has an acidic pH of around 3.5 (see
here).
My apologies for being late to the conversation. But I have been asked by a member to clarify this point.
I have two contexts to add to this idea. First, the chemical pH context, and second, the metabolic acidity and alkalinity context.
First, both the cation and anion of a salt create pH effects. Each has differential affinity for the hydroxide part of water and the proton part of water. Water spontaneously dissociates into (hydrated) hydroxide and protons, and any selective interaction with one over the other creates pH shifts. So potassium (versus sodium, lithium, rubidium and cesium) does have differential effects on water pH. But since such "alkali" ions are so dramatically unreactive, their solitary effects are very subtle compared to the myriad of complex organic molecules that can be "decorated" with anionic (negatively charged) groups (e.g., carboxylic acid, ketone, aldehyde, ester) and cationic (positively charged) groups (e.g., alcohol, amine, ammonium, ether). So it is natural and practical to focus on the conspicuous and dismiss the subtle.
Second, the terms
acid, acidifying and
alkaline, alkalinizing have a non-chemical meaning in the context of biological systems and metabolism. This is popularized by the macrobiotic classifications of foods, nutrients, substances and drugs into acid-forming and alkaline-forming categories. These categorizations were made based on traditional Eastern medical principles that other people can describe. But independently, Dr. Emanuel Revici derived a similar classification almost 100 years ago by exposing rodents to various foods, nutrients, substances and drugs and measuring their resulting wound pH shifts with pH meters. There is a 85% congruence between these two lists. East meets west.
Revici's "archaic" terminology for this (homotrophic, heterotrophic) was "translated" as acidic and alkaline, but this is not the same acid and alkalinity of chemical pHs, despite being measured by such methods. His terminology has also be translated as catabolic and anabolic, and as aerobic and anaerobic, respectively.
None of these translations is fully in accord with the modern uses of such terms. But since saying potassium is alkalinizing-anaerobic-anabolic in metabolic character and calcium is acidifying-aerobic-catabolic in character is quite awkward, it is simply described as alkaline, or anabolic, or anaerobic, with some kind of mutual understanding that this is a shorthand for the metabolic/biological meaning of the words.
If you want to know the chemistry and physics, the metabolic character of compounds turns out to be highly related to their charge when dissolved in water, their oxidative state and their electronic configuration. These do relate somewhat to pH, but it is also distinctly separate (as I understand it). When aerobic-acidifying-catabolic carboxylic acids and aldehydes are dissolved in water, they end up carrying a negative charge. In the case of carboxylic acids, it is substantial, and with aldehydes it is less. Catabolic elements (calcium, magnesium, copper, oxygen, sulfur, selenium) are electronically paired (they have an even humber of electrons in their outer orbitals. And the more oxidized organic structures are, the more likely they are catabolic-acidifying-aerobic. Alcohols and amines are reduced structures (fully loaded with hydrogen or hydride), carry positive charge when dissolved in water and are alkalinizing-anaerobic-anabolic in character. Among fatty acids, which are all acidic-aerobic-catabolic in character due to their carboxylic acid group, the higher oxidized PUFAs (polyunsaturated fatty acids) are among the most powerful catabolic-aerobic-acidifying structures that Revici ever quantified. Saturated fats are dramatically less acidifying. The structurally related fatty alcohols are very alkalinizing.
Experientially, there is no connection between the acidic or alkaline taste of a food or substance and its acid or alkaline metabolic effect. Lemon juice is very acidic (tart) on the tongue, but is substantially alkaline-anabolic-anaerobic in its metabolic effect. Sea vegetables (seaweeds) are powerfully alkalinizing-anaerobic-anabolic without having any conspicuous pH-associated taste.
Since I am new to this forum, I'd like any clarification from members as to whether this discussion is best kept as part of this thread or should be handled in a different manner. It is my considered opinion that this particular dimension of metabolism is highly relevant to autoimmune diseases and chronic fatigue states. But I also realize that it is highly complicated and is often counterintuitive in nature.
Advice and questions are welcome.
